Reversible mechanical and adhesive biogels with ion-electronic hybrid conduction and skin temperature-mediated dynamic interactions for multi-modal and self-powered sensing

Natural material-based conductive hydrogels are promising candidates for wearable electronics due to their excellent biocompatibility, high softness, and stable adhesion. However, it remains challenging to integrate high environmental tolerance, low interfacial impedance, high ionic conductivity, and switchable modulus and adhesion into a single platform for practical applications. Herein, we propose a material and structure concept of temperature-mediated multiple dynamic interactions and ion-electron hybrid conduction to fabricate high-performance multifunctional biogels with desired features. Skin temperature-mediated phase transition of gelatin and reversible dissociation-association of dynamic interactions allow the biogels to possess a high self-healing efficiency (95%) and reversible adhesion strength (44.96 kPa) with a switching ratio of 8.72. Ion-electron hybrid conduction facilitates the capacitive coupling process of ionic and electronic current, resulting in low interfacial impedance (56.63/29.68 k Ω at 10/100 Hz) and high electrical conductivity (ionic conductivity: 0.74 S m −1 and electronic conductivity: 0.059 S m −1 ). Benefiting from these superior properties, the multifunctional biogels demonstrate important applications in strain/pressure sensors, epidermal electrodes, and triboelectric nanogenerators. Intelligent gesture control and recognition systems are developed with the assistance of a convolutional neural network. This concept offers new opportunities for fabricating multifunctional and high-performance conductive biogels, paving the way for the development of intelligent flexible electronics.